During the 19th century's industrial revolution, jobs previously done in individual workshops became concentrated in factories. As workers endured difficult and often hazardous conditions together, they began to unite to express grievances. Among the demands

that unions fought for and eventually won was limiting the number of working hours, standardizing wages, eliminating child labor, and providing safe workplaces. The initial attempts to organize were strongly opposed by the bosses, and radical ideas were sometimes met with violence. The first third of the 20th century saw the full flowering of the labor movement as unions gained a foothold with factory workers and saw the passage of pro-labor laws as part of the New Deal.

Throughout all of this, music played a tremendous part in educating and inspiring workers, and songwriters from Joe Hill to Woody Guthrie made important contributions to America's labor movement by helping to raise consciousness about working conditions and the ways unions could help improve them.